Thanks for the reply!
I picked up the ‘Nut this evening and I’m definitely glad I opted for L. I’m going to replace the bars (I’m used to 810mm on the hardtail), put in a dropper and stick some SPDs on. Then I’m going to ‘have it’. Oh, and convert to tubeless as well.
I absolutely love my hardtail, though, and it will continue to be my workhorse bike. I ride a lot locally (the odd class bit of woodland/quarry interspersed with farm tracks and road), so the Bossnut will be reserved (mostly) for away days in the Peaks, Long Mynd and further afield. I try to get a couple of away trips in every 2-3 months, so this bike is a little luxury I’ve awarded myself for my 40th.